A CEO got entire 20 man dev team into boardroom and asked everyone to voice any concerns about technical debt, bad development practices, anti patterns as well as project management issues.

The 4 people who spoke up were all fired on the same day 3 or 4 weeks later. 7 more quit shortly after - as soon as they got any decent offer. 6 months later about a quarter of the 20 were still with the company.